The present invention relates to a method for producing NF.sub.3 by fused salt electrolysis of an electrolyte mixture which contains hydrofluoric acid salts of ammonia.
In industry NF.sub.3 has found use, inter alia, as a filler gas for flash bulbs, as a fluorination agent, as an oxidizing agent in rocket drives and as a plasma etching gas.
Compared with several other production methods, in practice, fused salt electrolysis of adducts of the type NH.sub.4 F.nHF has proved suitable to be carried out on a commercial scale. According to O. Glemser, J. Schroeder and J. Knaak, Chem. Ber., 99, pages 371 to 374 (1966), a good NF.sub.3 yield (23-32%) can be expected if the number n is between 1.2 and 1.8 and the fused salt electrolysis is carried out at approximately 130.degree. C. However, this is not accomplished without difficulties, as at such temperatures NH.sub.4 F released by sublimation has to be collected in a separate separator in order to prevent accidents due to blocking of the gas outlet pipes. Furthermore, with this method partially fluorinated amines are evolved, which tend to decompose explosively.